I. Field of the Invention
The present invention generally relates to collapsible therapeutic intravascular devices for treating certain medical conditions and, more particularly, relates to intravascular devices selectively configured of discrete components for selective occlusion of a vessel or vessel defect, shunting of flow, restricting flow or filtering flow in a vessel or organ, anywhere within the body's circulatory system. The devices made in accordance with the invention are particularly well suited for delivery through a catheter or the like to a remote location in a patient's vascular system within a patient's body to occlude, shunt, restrict or filter blood flow.
II. Related Art
A wide variety of intravascular devices are used in various medical procedures. Certain intravascular devices, such as balloon catheters, diagnostic catheters, stent delivery catheters and guidewires, are generally used simply to navigate, deliver fluids or other medical devices to specific locations within a patient's body, such as a selective site within the vascular system. Other, frequently more complex, devices are used in treating specific conditions, such as devices used in removing vascular occlusions or for treating septal defects and the like.
In certain circumstances, it may be necessary to occlude a patient's vessel, chamber, channel, hole or cavity such as to stop blood flow there through. In other cases, it may be necessary to create a flow restriction or to shunt flow from one vessel to another to treat abnormal cardiovascular conditions. In still other cases, it may be desirable to filter blood flow such as to prevent blood clots or emboli from passing from one location in a vessel to another.
Examples of selective occlusion are, without limitation, closure of a Patent Ductus Arteriosus (PDA), Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), Patent Foreman Ovale (PFO), Arterial Venous Fistula (AVF), an Arterial Venous Malformation (AVM) or a Left Atrial Appendage (LAA).
Mechanical embolization devices are well known in the art and sold commercially for occlusion of vessels in various locations within the vasculature. U.S. Pat. No. 6,123,715 by Amplatz and U.S. Pat. No. 5,725,552 by Kotula disclose intravascular occlusion devices fabricated from Nitinol braided metal tubular fabric which are heat set in molds to an expanded shape, but which can be compressed for delivery through a catheter to a treatment site, whereby the device, when urged out of the delivery catheter, self expands within the vasculature to occlude blood flow at the treatment site. The details of the various designs and configurations as well as methods of fabricating and using the devices are detailed in the aforementioned patents which are deemed incorporated in total herein by reference for any purpose.
An example of a shunting procedure is the shunting of blood between the portal vein and the hepatic vein, know as a Transjugular Intrahepatic Portosystemic Shunt (TIPS). Certain forms of congenital disease may require a communication between the right atrium and left atrium. Shunting may also be required for treating specific abnormal conditions, such as bi-passing vascular occlusions within an internal passageway. U.S. Pat. No. 6,468,303 to Amplatz et al, also incorporated in its entirety herein by reference for any purpose, describes catheter deliverable shunt devices manufactured in similar fashion to the previously discussed occlusion devices and also details their design and use.
Many defects that involve holes or openings in the septum of the heart allow blood to flow from the high pressure left ventricle to the lower pressure right ventricle causing excess blood flow to the lungs. The body's natural reaction is to constrict the vessels to the lungs to restrict blood flow. Over time this causes a thickening of the pulmonary arteries and ultimately to closure of smaller lung arteries and further complications if left untreated. Examples of flow restriction devices for treating such a condition, their design and use, are found in U.S. Pat. No. 6,638,257 to Amplatz which is also deemed incorporated in its entirety herein by reference for any purpose.
An example of a filtering procedure is a vena cava filter used to prevent passage of blood clots from the venous system to the lungs. Another filtering procedure involves prevention of emboli from balloon or stenting procedures from passage down stream into the heart while treating saphenous vein bypass grafts or preventing emboli from passing to the brain during carotid artery stenting procedures. An example of a filtering device for treating such a condition, it's design and use is found in U.S. Pat. No. 6,123,715 to Amplatz and U.S. Pat. No. 5,725,552 to Kotula as previously cited and incorporated by reference.
The occluding, shunting and flow restricting devices all use similar technology for fabrication and each device as detailed is formed of a single plurality of metal strands woven into a tubular braid. Due to the wide anatomical range of dimensions between premature infants and adult patients, variations between patients of even the same body size, and considering the number of various treatment modalities, one can appreciate the enormous number of sizes and types of devices that need to be manufactured and inventoried by both the manufacturer and the hospital. This represents a large amount of capital sitting on the shelf until the need arises for a particular type and size of device. To reduce inventory, would require that devices be ordered in advance as needed. This presents a problem for emergency cases when there is afforded no time for waiting to treat a patient while a device is manufactured or shipped from stock if available.
Therefore there is a need for medical devices of the class that can be assembled by either the manufacturer or preferably by the physician at the point of use from an array of component parts that meets the needs of physicians without undue delay or inventory cost. Furthermore, there is a need for a physician to be able to assemble a large number of custom devices suitable for a particular anatomical condition from a variety of components available in a medical device kit, or the like, made available at the point of use instead of stocking a large number of various types and sizes of assembled devices.
The present advance in the art solves these problems in an advantageous manner as will be explained in this specification.